The present invention relates to iron golf clubs.
Recently, attention has been focused on iron golf clubs with heads made of titanium. Titanium has a small specific gravity and high strength. Therefore, iron golf clubs with titanium heads enable the head size to increase and hence make it possible to enlarge the sweet spot.
In the field of golf clubs with titanium heads, particularly iron clubs, there have been developed clubs in which a metal having a large specific gravity is buried in the sole to lower the center of gravity of the clubhead. However, it is technically difficult to bury a different kind of metal in the sole, and this leads to a rise in the production cost and causes the rejection rate to increase.
Conventional iron golf clubs have been designed so that the ball contacts the sweet spot on the clubface at impact. However, the research conducted by the present inventor has revealed that the farthest distance is attained when the ball contacts the sweet spot at right angles to the clubface, and that the point where the farthest distance is obtained is not the sweet spot when the clubface meets the ball at a predetermined angle of tilt as is the case with iron golf clubs.